Flexible shafting.



W. F. BUTLER. FLEXIBLE SHAFTING. APPLICATION FILED PEB.9, 1912.

1,1 19,572. I Patented Dec.1,1914.

M agnfw 6g W ammw WILLIAM F. BUTLER, OF PENDLETON, INDIANA.

FLEXIBLE SHAFTING.

Specification of Letters Iatent.

Patented Dec. 1, 1914.

Application filed February 9, 1912. Serial No. 676,563.

To all whom it may concern: v

Be it known that I, WILLIAM F. BUTLER, of Pendleton, in the county ofMadison and State of Indiana, have invented a new and useful Improvementin Flexible Shafts, which improvementis fully set forth in the followingspecification and shown in the accompanying drawings.

The present invention relates to flexible shafts and more particularlyto the type embodying a plurality of links which are capable of relativelateral movement but are held together for simultaneous rotary movement;and an object of this invention is to so construct the links that theymay be made inexpensively from commercial or standard metal stock upon'automatic machinery,

while at the same time providing a simple and durable construction.

To these and other ends the invention consists in certain parts andcombinations of parts, all of which will be hereinafter described, thenovel features being pointed out in the appended claims.

In the drawings: Figure 1 illustrates a side and an end view of a stripof metal from which one of the links is formed; Fig. 2 illustrates aside and an end view of the link formed from the metal shown in Fig. 1;Fig. 3 illustrates a side and an end View of the stock from which theother link is formed; Fig. 4 illustrates an axial section and an endview of link formed from the stock shown in Fig. 3 before such link isconnected to the link shown in Fig. 2; and Fig. 5 illustrates the twoforms of links connected together end to end, the tubular link beingshown in axial section.

According to this invention a strip of metal preferably noncircular incross section, a square or other polygonal form having an equal numberof sides being most'desirable, is out in short strips or pieces 1 asshown in Fig. 1, the cutting preferably being performed by an automaticmachine to which the strip is fed. After the pieces have been out, theyare passed to forging or stamping devices which upset their ends toprovide enlargements. The base 2 of each of such enlargements is in theform of a polygon, preferably a square, and from such base rises sidewalls each of which curves outwardly at 3 in one direction only, on atrue arc, the arcuate portion merging into a flattened portion 4. whichmerges into an apex 5 forming a pyramidal portion becommercial stockwhich is preferably out by automatic machinery into short pieces 6, asshown in Fig. 3, and then is pressed, forged or stamped at its ends toprovide noncircular pockets '7 corresponding to the cross section of theenlarged portions of the link 1, in this instance, having a square crosssection. The diameters of these pockets are at least as great as thecylindrically formed inner wall 8 of the link so that shoulders 9 areprovided for cooperation with the en larged portions of the links 1,thus limitin axial movements ofthe links 1 in the links 6, while at thesame time permitting the apexes of the enlarged portions to project intothe cylindrical portions so that the straight faces of the enlargedportions may coiiperate with the internal or cylindrical walls 8 oflinks 6 in order to limit the lateral sidewise movement of' the links.

For uniting the links the ends of the tubular links 6 are turnedinwardly as at 10 for the purpose of confining the enlarged heads withinthe pockets 7 while at the same time permittingvlateral movements ofsaid links.

A flexible shafting constructed in accordance with this invention willcause all the links to turn together and at the same time'will permitrelative lateral movement of the links. The links are so formed thatthey may be made from commercial metal stock upon automatic machineryand in use thev will be very durable.

What I claim as my invention and desire to secure by Letters Patent is:

1. A link for flexible shafts comprising a connecting portion, andenlarged portions at its ends, each enlarged portion having a base inthe form of a polygon with an equal number of sides. the side walls ofthe said enlarged portion rising from said base, those portions of thewalls in proximity to the base being curved on true arcs, the arcs ofopposite walls having a common center and the portions of said sidewalls beyond the curved portions being flattened and merging to a pointor apex.

i 2. A link for flexible shafts comprising a connecting portion andenlarged portions at its ends, each enlarged portion having a squarebase, the side walls of which rise from the base and have those portionsin proximity to the base being curved on true arcs, the arcs of oppositewalls having a common center, and said side walls forming a. pyramidbeyond the curved portions.

3. A flexible shaft consisting of links of two forms, alternatelyarranged, one a tubular link comprising a central portion with acylindrically-formed inner wall and end portions provided with pocketscommunicating with the interior of the central portion, each of said endportions being polygonal in cross section and the inner ends of thepockets forming shoulders, and the other, a link comprising a centralportion and enlarged ends fitting in the pockets of the tubular links,said enlarged ends each having a base in the form of a polygon andcurved side walls rising from the base, the side Walls of the enlargedends closely fitting in said ockets to turn in engagement with the Wallsand being limited in movement by the shoulders at the bottoms of thepockets.

4. In a flexible shaft, the combination with link members havingenlargements at their ends, each enlargement having a polygonal base andside walls curved outwardly in one direction only, of tubular linkmembers havminers ing a central hollow portion with acylindrically-formed interior wall, and also having pocketed endportions, the pockets each having a polygonal cross section andreceiving one of the enlargements and each of said pockets having itsdiagonals greater than the diameter of the interior of the centralportion, thus forming shoulders which limit the movements of thefirst-named links within the tubular links.

5. A flexible shaft comprising links provided with enlargements atopposite ends, the extreme portions of said enlargements havingprojections, and tubular links alternated with the first-named links andhaving the enlargements of said first-named links fitted in their ends,said enlargements turning in engagement with the inner walls of thelinks, said tubular links having shoulders formed therein limiting themovement of the enlargements in the direction of the lengths of thetubular links, and the portions of the tubular links between theshoulders receiving the projections on the enlargements and byengagement with said projections limiting the lateral movements of thelinks.

WILLIAM F. BUTLER. Witnesses:

HOWARD WALK R, CHAs. E. Coornn.

